AT-CUR CRYSTAL ELEMENT MANUFACTURING PROCESS Russian patent published in 1998 - IPC

FIELD: microelectronics; manufacture of thin crystal elements for high-frequency piezoelectric devices such as crystal cavities and monolithic filters. SUBSTANCE: manufacturing process involves mechanical treatment of crystal blanks and their chemical and dynamic etching in acid solution doped with surface-active impurities such as dimethylformamide or butanol conducted at 348- 373 K in two stages. First stage includes chemical and mechanical etching in acid solution doped with butanol to produce blank having surface roughness equal to or greater than 0.04 mcm. During second stage, etching solution is doped with dimethylformamide to obtain surface roughness of crystal element not over 0.02 mcm. In either case, surface roughness is measured by etching traces along line which is at angle of 30 deg. to crystallographic axis X in crystal. Dynamic resistance of cavities manufactured using proposed process is in average 30% lower than that of prototype. In addition, yield of cavities with Q- factor as high as 15•10³ amounts to 75% compared to 60% of prototype. EFFECT: improved capacity and yield of high-quality crystal elements. 3 dwg, 1 tbl